POS0199 DETECTION OF SARS CoV-2 ANTIBODIES FOLLOWING VACCINATION IN PATIENTS WITH RHEUMATIC MUSCULOSKELETAL DISEASE (DECODIR) – AN INTERIM REPORT FROM A DANISH PROSPECTIVE COHORT STUDY
Authors: C. Graversgaard, K. Schreiber, R. Petersen, H. Jakobsen, A. B. Bojesen, N. Steen Krogh, B. Glintborg, M. L. Hetland, O. Hendricks
Journal: Annals of the Rheumatic Diseases (2022)

Background During the COVID-19 pandemic, it remains a major concern whether patients with rheumatic musculoskeletal disease treated with conventional (cs) or biologic (b) disease modifying drugs (DMARDs) exhibit an adequate immune response to the currently available SARS-CoV2 vaccines. There remains an urgent need for more data on SARS-CoV-2 vaccine efficacy to inform healthcare providers on the efficiency of the applied vaccination, potential need of and period for booster and/ or re-vaccination. Objectives To assess and compare the efficacy of the SARS-CoV2 vaccines BNT162b2 vaccine (Pfizer/BioNTech) and mRNA-1273 vaccine (Moderna). ( The vaccines were administered as part of the Danish vaccine roll out and offered each with two doses and approximately four weeks apart ). Patients’ SARS-CoV2 IgG serum level was used as proxy to determine vaccination response. Methods We established the ‘Detection of SARS-CoV2 antibodies in Danish Inflammatory Rheumatic Outpatients’ study (DECODIR) as a longitudinal prospective cohort study. Patients with rheumatoid arthritis (RA), spondyloarthropathies (SpA) or psoriatic arthritis (PsA) receiving their outpatient treatment and monitored in the Danish DANBIO registry at the Danish Hospital for Rheumatic Diseases (DG), Sonderborg were included (April - June 2021). Bloods, patient reported outcome measurements (PROMS), clinical data and treatment information (cs/bDMARD) were collected at baseline (prior to vaccination) and after six weeks and six months. SARS-CoV2 IgG levels in serum were assessed by ELISA (ThermoFischer), and manufacturer’s cut-off (&gt;=10 EliA U/mL) selected as definition of sufficient IgG response. Associations between antibody response, age, gender, disease (RA/PsA/SpA), treatment with no or cs/bDMARDs and disease activity were tested using proportional odds regression and bootstrapped tests of medians. Results were reported using mean, median (IqR) and bootstrapped 95% confidence interval (CI) of the median. Results A total of 243 patients were included at baseline and after six weeks; at six months’ follow-up data were available for 233 patients. After six weeks, vaccination was followed by a significant increase in IgG levels (median of &lt;0.7 EliA U/mL at baseline versus 36.5 EliA U/mL). Patients treated with a combination of both cDMARD and bDMARD had significantly lower IgG levels compared to patients without any DMARD treatment (8,2 EliA U/mL vs 19.5 EliA U/mL (p&lt;0.001)). Patients treated with oral prednisolone (any dose) also showed significantly lower median IgG levels compared to patients without DMARD treatment (3,8 EliA U/mL vs 19.5 EliA U/mL (p&lt;0.01)). The actual measurements six months after baseline demonstrated a significant decrease of IgG levels for the whole study population (median of 16 EliA U/mL at six month vs 36.5 EliA U/mL at six weeks, p &lt; 0.001) (Figure 1). Figure 1. IgG-level stratified by treatment Similar to week 6, lowest response rates were found in patients treated with prednisolone or combination of csDMARD and bDMARD. After 6 months, the proportional odds model revealed significantly lower median IgG antibody level in patients who received Pfizer compared to Moderna (median 15 EliA U/mL (95%CI: 13-18) vs 44.5 EliA U/mL (95%CI: 36-83) (p&lt;0.001). Conclusion IgG levels decreased markedly six months after the initial double dose regimen. Patients treated with a combination of cs/bDMARD or oral prednisolone are at higher risk of inadequate vaccine response as measured by IgG level. Our results support the decision for the need of a third booster vaccine in patients with inflammatory rheumatic diseases, especially in the case of cs/bDMARD combination treatment and prednisolone. The data may indicate a need for further revaccination in these patients. Reference [1]Schreiber K. et al. Reduced Humoral Response of SARS-CoV-2 Antibodies following Vaccination in Patients with Inflammatory Rheumatic Diseases— an Interim Report from a Danish Prospective Cohort Study. Vaccines 2022, 10(1), 35. Acknowledgements We acknowledge all patients contributing to the DANBIO registry. The Danish Rheumatologic Biobank is acknowledged for handling and storage of biological material. Lab technician Charlotte Drachmann is acknowledged for her assistance Disclosure of Interests Christine Graversgaard: None declared, Karen Schreiber Consultant of: UCB Advisory Board, Randi Petersen: None declared, Henning Jakobsen: None declared, Anders Bo Bojesen: None declared, Niels Steen Krogh: None declared, Bente Glintborg Grant/research support from: AbbVie, BMS, Pfizer, Merete Lund Hetland Grant/research support from: AbbVie, Biogen, BMS, Celtrion, Eli Lilly Denmark A/S, Janssen Biologics B.V, Lundbeck Fonden, MSD, Pfizer, Roche, Samsung Biopis, Sandoz. MLH chairs the steering committee of the Danish Rheumatology Quality Registry (DANBIO), which receives public funding from the hospital owners and funding from pharmaceutical companies. MLH co-chairs EuroSpA, which generates real-world evidence of treatment of psoriatic arthritis and axial spondylorthritis based on secondary data and is partly funded by Novartis., Oliver Hendricks Grant/research support from: AbbVie, Novartis, Pfizer